Rectifier and detector.



PATENTED FEB. 11, 1908.

G. W. PIERCE. RECTIFIER AND DETECTOR.

APPLICATION FILED APR.5,1907.

UNITED STATES PATENT 1 oEErcE.

GEORGE W. PIERCE, CAMBRIDGE,'MASSACHUSETTS, ASSIGNOR TO MASSACHUSETTS WIRELESS EQUIPMENT COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF NEW YORK.

RECTIFIER AND DETECTOR.

' Specification of Letters Patent.

Patented Feb. 1 1, 1908.

Application filed April 5| 1907- Serial No. 3661568.

To all whom it may concern:

Be it known that I, GEORGE W. PI RoE, a

citizen of the United States, and resident of Cambridge, Middlesex county, Massachuf electric wave signaling systems.

v In practicing my invention I employ as a rectifier or detector a substance known as hessite which occurs in nature usually as telluride of silver,. although the silver is sometimes wholly or partially replaced by gold. I have discovered that this substance is asymmetrically conductive when used in connection with small currents, and I have also discovered that by reason of this property of asymmetrical conductivity and .pos-

sibly of other unknown roperties'this substance when properly-p aced between conductive electrodes is highly sensitive as a receiver for electromagnetic waves;

The rectifying or detecting material may be utilized in many and various shapes and may be connected inthe circuit of the receiving or other apparatusin various ways.

For the purpose of illustration I have shown several forms ofrectifiers and detec tors in the accompanyin drawings in which 7 Figures 1 to 3 show di erent ways in which the recting or detecting material may be connecte with electrodes. -Fig. 4 shows a detector arranged in a direct connected receiving system, and Fig. 5 shows a detector arranged in an inductively coupled receiving system.

In the arrangement of Fig. 1 a piece a of hessite, is held in a clamp, the jaws b and c of which form electrodes making contact with the rectifying or detecting material.

I have secured the best results by cutting a piece from a crystal on a plane substantially at right angles to its axisand engagingone of the electrodes with a oint or corner of the crystal so that a sma area of contact 1s secured.

' In the arrangement of Fig: 2 a crystal or fragment of acrystal d is held inan ordinary suitable form of indicatin 'nected re ceivin jewel mounting and a point of the crystal is engaged by a metallic, sprin e. "The contact between the spring e an the detecting material ma be adjusted by a screw f to secure the character of contact which will give the best results.

In the arrangement shown .in 'Fig. 3"a piece 9 of hessite isjsealed in the end of aglass tube It. The piece g isin contact with a mass of conducting liquid within the tube It and with a second mass of conducting liquid -within a receptacle 5, the masses, of liquid,

forming the electrodes which contact with the iece g. The liquid should'be such that it W' 1 not act destructively upon the piece 9.

Any-other-suitable form and arrangement .of the electrodes and of the rectifying or detecting material may be employed which may be found desirable or best suited to. the conditions under which the particular apparatus in which'the invention is embodied is to be used.

The constructions described or any other suitable construction may be utilized to rectify small oscillatory currents wherever 4 such rectification is desirable as for instance in investigating telephonic currents. These or other suitable construction may also be utilized as wave detectors or receivers in any suitable or well known receiving apparatus for wireless telegraphy systems, and any device may be employed therewith such or instance as a relay, a galvanometen'a telephonic receiver, a capillary electrometer, etc.

In 4 a receiver embodying the invention is shown included in a direct consystem, in which a telephonic receiver is connected in'shunt about the detector. Asmall battery. Z may be in- .cluded in the indicator circuit altho'ugh'I have secured as good if not better results without a battery.

When used the battery current lowers the resistance .of the rectifier since'the resistance of therectifying material decreases with the increase of current, and by reason of the fact that the current through the detector is not proportional to the voltage an additional rectification is obtained" under some cond1t1ons:

InFig. 4 a receiver m embodyin the invention is shown included in an in uctively coupled receiving system. In this case the sistini of .crystalline telluride of silver.

rectifier foroscillatory currents consisting of hessite.

4. A receiver for wireless tele raghy systems consisting of a compound 0% s' ver and tellurium in contact with two electrodes.

5. A rectifier for oscillatory currents consisting of hessite in contact with two electrodes 6. A receiver for wireless telegraphy systems consisting of hessite in contact with two electrodes.

In witness whereof, I have hereunto set my hand, this 19th day of March 1907.

. GEORGE W. PIERCE.

In the presence of IRA L. FISH, KATHARINE A. DUGAN. 

